Rotary-drum machines



United States Patent Inventor Reginald Thomas Hopkins [56] ReferencesCited atf r gland FOREIGN PATENTS P 928,042 5 1955 Germany 7. 210/146Filed Oct. 18, 1968 Patented Nov. 10, 1970 OTHER REFERENCES AssigneeGeneral Motors Corporation German Printed Application 1,158,003,November 1963,

Detroit, Michigan 210- 146. a cm'ponum of Delaware Primary Examiner-J.L. DeCesare Pmmy 2, Att0mey-- F. M. Ritchie and w. E. Finken GreatBritain 49,789/67 1 ABSTRACT: A centrifugal extraction machine includesa casing, a rotary drum within the casing, a lid on the casing opena-:gT? i2% Q ble for access to the drum, and a lid latch to secure the lidin a raw closed position on the casing. The machine has a brake to U.S.Cl 210/146, brake rotation of the drum, and an interlock between the210/368 brake and the latch which interlock is operable by mechanicalInt. Cl 1304b 7/06 reaction torque of the brake, when the drum is beingbraked, Field of Search 210/146, to block release movement of the latchand prevent opening of 368 the lid while the drum rotates.

Patented Nov. 10, 1970 r ("0,539,011

Sheet I of 4 Inventor A Home y 1 ROTARY-DRUM MACHINES This inventionrelates to rotary-drum machines, for example spin driers, clothes washermachines having centrifugal drier drums, or other centrifugal extractionmachines having a lid to cover the drum which is 'close d by a latchwhenever the drum is rotating butrequires to be opened to fill or emptythe drum.

By the invention untimely opening of the lid when the drum is stillrotating is prevented by aninterconnection between the catch of the lida'nd'the rotation of the drum.

The scope of the invention is defined by the appended claims; how theinvention may be performed is, particularly described below withreference to the accompanying drawings. i

a One example of a machine in accordance with the invention is shown inFIGSJ to 4 ol' the drawings, in the form of a spin drier for domesticlaundry use. In the drawings:

FlCbl is a diagrammatic view, partly in section of a spin I drieraccordingto the inventio n, with some parts omitted for clarity;

HO. 2 is a plan of a brake spinner plate according to the inventions XFIG. 3 is a plan of a stop device according to the invention;

FIG. 4 is a plan ofthe lid latchof FIG. 1;

FIG. 5 is a diagrammatic viewtsimilar to FIG. I, of second embodiment ofspin drier for domesticlaundry use;

FIG. MS a planof the brake of FlG. 5ointhe direction of the arrow A;

FIG. 7. is a side'view in the direction of the arrow B in FIGS. 5 andtLofthe cable and fixture of FIG. 5;

when the lid unlatched. Within the casing a drum 5 is mounted on ahollow shaft 7 jou rnaled in bearings I05, 106 on a spindle 9 secured toasupport it) near the bottom of the easingl. Near itslower end, theshaft 7 has an enlargement H with a peripherulgroove thci'cin, whichforms a pulley fora drive belt (hotshown) from an, electric motor (alsonot shown). The shaft 7 extends slightly below the enlargement 11. Arotatable brake assemblyis attached to the bottom 13 of the shaft 7, andconsists of a brake spinner plate 15 sandwiched between themae hinedundersurface 17 of the enlargement 1.1 arid a pressure plate 19, byhelical compression springs 21 threaded on bolts 23 screwed into thebottom 13 of the shaft 7. The spinner plate has frictionpads 25 on eachface, and has two diametrically opposed lugs 29, 31 on itsperipherytFlG. 2); The lid 3 hasa fixed latch member 33 with twooppositclyfacing barbs 35; .37- along its length, one barb 37 beingbelow the otherbarb'35. A spring-loaded horizontal latch plate39.slidably mountedinthe casing l has a knob 41 on its outsideend-extendingthrough the casing wall. A helical from stop 63, alsoprojects up from the support 10. The push rod 49 also has a contact 67for making and breaking a drum drive motor energizing circuit through amicroswitch 69 secured to the casing 1.

When' wet clothes are loaded into the drum 5 and the machine operated,water or any other liquid is centrifuged out through apertures (notshown) in drum 5. The centrifuged compression spring 43 abuts at oneenda stop 45 extending downwardly from theunderside of the plate 39.near its inner end, the other end of the spring abutting against afixed abut ment 145. Thus the spring 43 acts to urge the latch plate 39outwardlyof the casing."l"he plate 39has a slot 47 in it (FIG.

4) whose length is suff cient to allow the passage therethrough of thelatch member 33 and one o fthe barbs 35,37 but not the latch member andboth barbs. A vertical push rod 49 is mounted for a'xi al and rotarymovement in brackets 57, 157;v on the side of thecasing l. Thepush rod49has a cranked.

lower end, 149 terminating in a short upturned vertical length or tall51. A helical compression spring 53 threaded on the rod 49 abuts at oneend nstop 55 on therod and at the other end abutsthe bracket 57 iixed tothe casingl forthe push rod 49. A cam 59is fixed on theupper end of thepush rod. A helical tension spring 61 "(FlCrS. I and 3) is connectedbetween the cranked end 49 of the push rod 49 and the casing] and holdsthe pushrod end 149 against a stop 63projecting up from the liquidcollects on a partition 200 in the casing l, and may be drainedtherefrom by some suitable means (not shown).

When the spin drier is operating any attempt to open the lid isprevented by the use of the mechanical reaction torque of the brakingenergy of the spinning drum to lock the lid until the drum is completelystationary. When'the drum is charged with laundry the lid is closed andlatch member 33 abuts the end of the push-rod 49 and depresses itagainst the pressure of the spring 53. This downward movement of thepush rod brings the contact 67 into engagement with the microswitch 69and completes the circuit for energization of the motor to rotate thedrum 5. As the lid is closed so the barb 37 of latch member 33 passesfreely through the slot 47, the barb 35 then passes through the slot 47by pressing the plate 39 inwards against spring 43, and the plate 39 isurged outwardly again by the spring 43 to overlie the barb 35 to preventupward move. ment of the lid and so hold it closed. If the operator nowpushes knob 41 'to move the slidable plate 39 inwards and releasethelid, then the upper barb 35 passes up through the slot 47 as the latchmember 33 is pushed up by the push rod 49 raising the lid 3 slightlyuntil the lower barb 37 contacts plate 39, which it does by virtue ofthe shifted position of plate 39. The upward movement of the rod 49 (tobroken line position, FIG. 1) moves the contact 67 away from themicroswitch 69 and breaks the motor drive circuit to deenergize themotor. The upward movement of rod 49 also brings its tail 51 up to thepath of the lugs on the brake spinner 15 which is revolving with thedrum shaft 7. One of the lugs hits the tail 51 and pushes it against thepull of the tension spring over from stop 63 against stop 65 The tail 51holds the brake spinner fast while the shaft 7 continues to revolve. Thefriction pads 25 still bear against the undersurface of the enlargementII and against pressure plate 19 and exert a braking effort on themwhich effort will depend upon the coefficient of friction between thebrake pads 25 and the surface on which they bear and the pressureexerted by the spring 21. The reaction torque of this braking effortwill be available as a tangential force exerted on the restraininginfluence; that is the stop 65, and will remain substantially constantuntil the drum is brought to rest. The movement of the tail 51 from stop63 to stop 65 turns the rod 49 through the same angle. The cam 59 isalso turned and this turning brings. it into contact with the stop 45 onthe slidable latch plate 39 and holds the latch plate 39 against returnoutward movement when knob 41 is released by the operator. Because thereturn movement of the plate 39 is stopped before it has movedsufficiently to bring the slot 47 into line with the lower barb 37 thisbarb cannot yet pass up through the slot to release the latch member33and allow the lid to be opened fullyby the spring hinge 4. The push rod49, cam 59 and slidable plate39 are held in their places until the drumstops completely since the brake reaction torque is substantiallyconstant and adjusted so as to be greater than the force exerted-v bythe spring 61. As soon as the drum stops rotating spring 61 pulls theportion 149 of rod 49 back against thestop 63, and so rotates rod 49 tomove cam 59 out of contact with the stop 45. The slidable plate 39 isnow free to return fully outwards under spring pressure 43 and so bringthe slot 47 into line with the lower barb 37 which can now pass throughit and so completely release the latch member 33 so that the lid canopenbecause ofits spring-loaded hinge 4.

The spin drier illustrated in FIGS. 5 to 10 has a sheet metal casing 10with an opening at the top closable by a lid 11 secured to the casing bya spring-loaded hinge 12. A drum and direct-drive electric motor aremounted as a unit l3 vertically within the casing. the drum [3A beingsupported above the motor 131! by a drive shaft 14. The casing containsa transverse partition 200A. This partition has a central aperture 2008.A drum and direct-drive electric motor are mounted as a unit 13vertically within the casing, the drum 13A being supported above themotor 138 by a drive shaft 14. The motor 138 is mounted on the undersideof the partition 200A by resilient mounts 13C, and the drive shaft 14extends through the aperture 20013 and supports the drum 13A above thepartition. When wet clothes are loaded into the drum 13A and the machineoperated, water or any other liquid is centrifuged out through apertures(not shown) in drum 13A. The centrifuged liquid collects on partition200A and may be drained therefrom by some suitable means (not shown).The drive shaft 14 extends below the motor and on this extension 14Athere is fixed a brake disc 15 for frictional engagement by a brakecaliper l6 fitted to a slidable plate 17. The slidable plate 17 ismounted on studs 18 on the underside of the motor and to one side of theshaft extension 14A. These studs engage in slots 19 in the plate 17 sothat the plate can be moved along the length of the slots. At one endthe plate 17 has a fitting 17A for one end ofa Bowden control cable 50,and at the opposite end the plate has two downwardly projecting opposedlugs 178, one on each side, through which a spindle 20 is fixed to forma pivot for the brake caliper 16. The brake caliper 16 has two opposedflat rectangular plates 21, 22 pivoted at one end on the spindle 20. Thetwo plates 21, 22 are urged apart by a helical compression spring 23fitted between them adjacent their pivot end. At the opposite end, theplates are connected together by a toggle joint 24, the limbs of whichare held normally in line (full line position FIG. 5) by the compressionspring 23. Secured to the centre hinge of the toggle joint is one end ofa helical tension spring 25, the other end of which is secured to abracket 26 on the motor. The plates 21, 22 each have a pad 120 offriction material secured on their mutually opposed surfaces. Thecaliper l6 and slidable plate 17 are so mounted with respect to theshaft 14 that the brake disc 15 is sandwiched between the plates 21,22of the caliper. A vertical rod 27 mounted in brackets 27A and 278 foraxial and rotary movement, is urged upwardly within the casing by ahelical compression spring 28 threaded on the rod, and having one endabutting a stop 28A on the rod while the other end abuts the bracket278. The rod 27 has a cranked lower portion 127, which has a flattenedend 29. The Bowden control cable 50 connects this end of the rod withthe slidable plate 17 in the manner explained below. Theouter casing 50Aof the Bowden cable is secured at one end to the bracket 26 on themotor, and near its other end to a support 202 on the base of the casing10 (see FIG. 7). A helical compression spring 30 is threaded on to theend of the cable 50 which passes through the flattened end 29 of the rod27 and has fixed to its end a collar 150 bearing against spring 30. Asleeve 31 is also fixed to the cable 50 and abuts the flattened end 29of the rod on the opposite side from the spring 30. The sleeve 31 isslidable over the outer casing 50A of the cable.

A lever 32 is pivoted at 132 on a support at the base of the casing. Onearm 32A of the lever abuts the cranked portion 127 of the rod 27, whichis held against the arm 32A by a helical tension spring 33 connectedbetween the cranked portion 127 of the rod and the casing 10, while theother arm 328 forms a foot pedal protruding from the casing. At itsupper end the rod 27 has a cam 34 which can be brought into engagementwith a pin 35 on a spring-loaded pivotable slotted latch plate 36,engageable by a barbed latch member 37 on the lid 11. The latch member37 has two oppositely facing barbs 38, 39 one below the other. The latchplate 36 is supported in a fixed bracket 236, in which it is pivoted ona pivot pin 237, and spring-loaded in one direction about the pin 236 bya torsion spring 238.

When the spin drier is operating, any attempt to open the lid isprevented by the use of the mechanical reaction torque of the brakingenergy of the spinning drum to latch the lid until the drum iscompletely stationary. When the drum is loaded, the lid 11 is closed,which causes the latch member 37 to abut the end of rod 27 and depressit against the pressure of spring 28. This downward movement of the rod27 brings a stop 2S0 thereon into engagement with a contact arm 251 of amicroswitch 252 and moves it to close an electric circuit to energizethe motor to spin the drum. As with the embodiment according to FIGS.'1to 4, the slot 136 in the movable latch plate (slot 136 in this presentcase) is of sufficient length to allow the passage through it of one butnot both of the fixed latch member barbs (38 and 39 in the presentcase). As the lid 11 is closed the barb 39 on the latch member 37 passesfreely through the slot 136 in the pivotable latch plate 36, and thebarb 38 then passes through by the necessary pivoting of the plate 36against spring 238, which then returns the plate 36 so that the upperbarb 38 engages the underside of the plate 36 to latch the lid. Bothbarbs 38 and 39 can pass freely through a wider slot 236A in the bracket236.

If the foot pedal 32B is now depressed, while the drum is spinning, themovement of the pedal lever 32 about its pivot causes the inner arm 32Aof the lever to push against the cranked portion 127 of the rod 27 andmove it against the pull of the helical tension spring 33. Thus rod 27is turned, causing cam 34 to contact pin 35 and effect sufficientpivoting ofplate 36 to bring slot 136 into alignment with barb 38,allowing the latch member 37 to be pushed up by the rod 27 under thepressure ofspring 28 until the lower barb 39 contacts the plate 36 andis thus prevented from passing up through the slotted plate, and soholds the lid latched. This upward movement of the rod 27 also breaksthe contact at 250, 251, to dcencrgize the motor.

The movement of the cranked portion 127 of rod 27 moves the Bowden cable50 (movement from full line to broken line position in FIG. 7). Thismovement of the cable 50, caused by the pressure of rod end 29 on sleeve31 moves the slidable plate 17 in its slots (to the left in FIG. 5,moving from the full line position to the broken line position). Thismovement of the plate pulls the toggle joint 24 against the resistanceof spring 25 and so causes the joint to bend. This bending of the jointpulls the plates 21, 22 nearer to one another and brings the pads intocontact with the rotating brake disc l5 which is squeezed between them.The rotation of the disc 15 against the friction pads 120 inducesfrictional drag tending to pull the plates round with the disc. Thisdrag, by moving the plate 17 further to the left in FIG. 5 tightens thepads 120 further against the disc, and the brake is in effect aself-energizing one. The drag pulls the cable 50 further against thepressure of spring 30 and so pulls the rod end 127 which causes the rod27 to turn further to hold the cam 34 against the pin 35 on the latchplate 36 and keep the lid locked. The reaction torque of the brakingeffort of the pads 120 on the disc 15 will be available as a forceexerted on the plate 17 and will remain substantially constant until thedrum is brought to rest. This force is transmitted by the plate 15through the cable 50 to the rod 27 to keep the lid latched. The reactiontorque of the brake is substantially constant over the whole of rundownperiod; and, therefore, if the various spring forces are so chosen thatthe slidable plate 17 moves quickly to the left after the initiatingforce is applied, then the plate 17 will remain in that position untilthe drum stops completely. Then, the combined action of springs 25, 28,30, 33 returns the mechanism to its original position and releases thelid 11 by allowing plate 36 to pivot under its spring loading until theslot 136 is in alignment with the lower barb 39 which then passesthrough the slot and so completely release the latch member 37, so thatthe lid can open. The spring 30 acts as a return spring for the controlcable 50.

The passage of rod 27 through the partition 200 is sealed by a flexibletelescopic boot" 201. The centrifuged liquid collects above partition200, as in the case of the first embodiment described above.

In the first embodiment described above (FIGS. 1 to 4) the vertical rod149, 49, acts as an interloek" between the latch and the brake. Asimilar interlock is provided by the corresponding parts in the secondembodiment (FIGS. 5 to 10).

I claim:

1. A centrifugal extraction machine including, in combination, a casingwith an aperture therein, a lid hinged to the easing and arranged toclose the aperture, a latch member having two locking positions attachedto said lid and extending axially into said casing, a manually actuatedlatch plate, a drum rotatably mounted within said casing and accessiblethrough said aperture, a drive shaft connected to said drum, an electricmotor driving said shaft, control circuitry for saidmotor, a I switch insaid control circuitry, a brake device attached to said drive shaftoperable to brake rotation of said shaft and said drum, a push rodmounted for axial and rotational movement within said casing, latchblocking means attached to the upper end of said rod, movement of saidlid to a closed position causing the engagement of said latch with saidlatch plate in a first locking position and simultaneously moving saidrod axially downwardly within said casing and closing said controlswitch, and brake actuating means attached to the lower end of said pushrod, manual actuation of said latch plate to a position disengaging saidlatch member from its first locking position causing said push rod tomove said latch member upwardly into a-second latching position whileopening said control switch, said brake actuating means coacting withsaid brake device to angularly move said push rod to position said latchblocking means to prevent disengagement of said latch from its secondlocking position while said drum continues to rotate.

2. A machine according toclaim 1 wherein said latch member comprisesoppositely extending barbs axially spaced to provide the two latchingpositions, said latch plate being 3. A machine according to claiml'wherein the latchblocking means comprises a cam rotatable to block thelatch against release as long as said rod remains moved angularly bysaid brake disc lug.

4. A machine according to claim 1, wherein the brake device comprises abrake disc having a peripheral lug, and two parts rotatable withthe drumand sandwiching said brake disc under a spring load; and said push rodincludes an abutment movable into engagement with said peripheral lug toarrest rotation of the brake disc and thereby brake the drum and applyto the disc said braking reaction torque.

5. A machine according to claim 1, wherein the brake device comprises abrake disc fixed for rotation with the drum and nonrotatable brakeplates sandwiching the brake disc and movable towards it.

6. A machine according to claim 5, in which the brake plates are hingedand are connected by a toggle joint, bending of which operates to movethe brake plates towards the brake disc.

7. A machine according to claim 6, in which the hinged brake plates areslidable to effect bending of the toggle joint.

